Year 1453 (MCDLIII) was a common year starting on Monday of the Julian calendar, the 1453rd year of the Common Era (CE) and Anno Domini (AD) designations, the 453rd year of the 2nd millennium, the 53rd year of the 15th century, and the 4th year of the 1450s decade.

In April, the forces of the Ottoman Empire began besieging the Byzantine capital of Constantinople. The city's fall and the destruction of the empire in May sparked fear and religious fervor against the Ottomans across Europe. Pope Nicholas V issued a crusading bull and attempted to negotiate a peace in the ongoing war in northern Italy, which saw Venice and Naples fight with the forces of Florence, Milan, and their French allies. In July, France routed the forces of England at the Battle of Castillon, and subdued the last English holdouts over the following months, ending the Hundred Years' War and English territorial control in France. The Ming dynasty of China was troubled by the growing power of the newly-proclaimed Khagan Esen Taishi in Mongolia. A diplomatic incident occurred when an embassy mission from the Japanese Ashikaga shogunate rioted and attacked Chinese civilians. Violent succession disputes broke out in several countries, including the Ryukyu Kingdom in Okinawa and the Mamluk Sultanate of Egypt.

A "mystery eruption" occurred at an unknown location in the northern hemisphere in late 1452 or early 1453, beginning a 15-year period of colder weather across the hemisphere. A major drought continued in the Aztec Empire, leading to famine and many deaths. China was devastated by catastrophic flooding along the Yellow River and an exceptionally cold winter.

A major volcanic eruption of unknown source likely occurred somewhere in the Northern Hemisphere in late 1452 or early 1453. The Kuwae caldera in Vanuatu was previously seen as a candidate for this eruption, but ice core analysis has instead linked it to another mystery eruption in 1458. Attested through dendrochronology (analysis of tree rings) across the northern hemisphere for 1453, temperatures decreased by 0.4–6.9°C (0.7–12.4°F), beginning a 15-year cold period.

Sayf al-Din Jaqmaq, sultan of the Mamluk Sultanate of Egypt since 1438, died on February 13. His son Al-Mansur Uthman, only 18 years old, ascended to the throne; desperate to avoid being overthrown for his youth, Uthman attempted to purchase the loyalty of various high-ranking mamluks using heavily debased coinage. Supreme Commander Sayf al-Din Inal led a coup d'état alongside his Zahiri emir allies against the young sultan, seizing the Cairo Citadel. Inal was accepted as sultan by Abbasid Caliph Al-Qa'im in April.

Hostile relationships continued between the Ming Dynasty and the growing Oirat confederation of Esen Taishi. Esen had captured the Yingzong Emperor in battle four years prior, and killed Northern Yuan leader Taisun Khan early in the previous year. Early in the year, the Minister of War Yu Qian considered a plan for an offensive campaign against the Oirat and Mongols, but ultimately focused on maintaining the northern border, unwilling to disrupt the newly reformed command structure of the Ming military. Having dominated the Mongol tribes after his defeat of Taisun, Esen declared himself Khagan of the Northern Yuan, becoming the first non-Borjigin to do so. The alarmed Ming government heightened border security, and debated whether to recognize Esen as Khagan. However, Esen's declaration led to significant internal conflict against his rule.

A recent series of annual floods worsened in central China, with the Yellow River devastating Henan. Urgent repairs to dikes along the Grand Canal were initially unsuccessful, leading to the appointment of the engineer Xu Youzhen to supervise efforts to maintain the canal and vital grain shipments to Beijing. An exceptionally cold winter caused heavy snow across northern and central China at the end of the year, with many deaths reported in the icebound Huai River valley. Following years of unrest among the Yao and Miao peoples, a regional uprising against Ming rule broke out in Guizhou and Huguang. The somewhat unstable political legitimacy of the Jingtai Emperor in the wake of Yingzong's capture was heightened after the death of Zhu Jianji [zh], his son and heir apparent, on December 18.

After a twenty-year halt, a large Japanese tribute mission was dispatched by the Ashikaga Shogunate to the Ming court. The envoys were angered by court officials' refusal to pay high prices for the wares, and rioted along their return journey, looting civilian houses in Lingqing, Shandong, and attacking officials sent to investigate. The Jingtai Emperor decided not to capture the riotous diplomats, hesitant to upset diplomatic relations with Japan.